PhD dissertation “Nature-based solutions to address water challenges in the Andean region: a mixed-methods approach”, by Yarima Recalde Aza

Urban water management in the Andean region faces growing pressures from climate change, rapid urban expansion, and persistent social inequalities. These challenges make it increasingly difficult for cities to ensure reliable, safe, and equitable access to water. In this context, Nature-based Solutions (NbS) have gained attention as a promising way to complement traditional infrastructure. They include both ancestral practices – such as amunas, ancient infiltration canals; and qochas, high-altitude ponds used to store rainwater – and modern green infrastructure that helps improve stormwater management, enhance aquifer recharge, and support climate resilience. However, despite their potential, NbS are not yet widely implemented due to institutional, technical, financial, and socio-cultural barriers.

Yarima Recalde’s thesis investigates these limitations and develops practical tools to strengthen the integration of NbS into water management in urban and peri-urban areas of the Andes. Through a systematic literature review and a mixed-methods study involving experts and local actors (e.g. surveys, semi-structured interviews, comparative analysis), the researcher identified 26 types of nature-based solutions, along with 36 barriers and 19 enablers that shape their implementation. Most documented NBS cases are concentrated in Peru and Ecuador, primarily addressing water scarcity (25%), flood risk (19%) and water contamination (16%).  The most pressing barriers relate to governance fragmentation, political discontinuity, and limited technical and financial capacity, while key enablers include inter-institutional coordination, capacity building, and diversified financing.

Building on this evidence, the thesis proposes 7 guiding principles and an evaluation framework designed specifically for Andean contexts. These tools support the selection and early-stage assessment of nature-based solutions by incorporating key dimensions such as governance, legal integration, community participation, ancestral knowledge, and territorial resilience. Ultimately, the thesis aims to provide actionable guidance to promote more effective, equitable, and sustainable water management solutions in the region.

The doctoral thesis was directed by Dr Ignasi Rodriguez-Roda and Dr Alexandra Popartan and developed in the Laboratory of Chemical and Environmental Engineering (LEQUIA), a multidisciplinary research group of the University of Girona renowned for its activity within the water field. The dissertation, which is open to the public, will be held on Wednesday 28th January 2026 at 16:00h at UdG Faculty of Sciences (carrer Maria Aurèlia Capmany, 61, Campus Montilivi, Girona) and online on Microsoft Teams.